【作者】 郭印；

【导师】 白晓红；

【作者基本信息】 太原理工大学 ， 岩土工程， 2004， 硕士

【摘要】 近几年来，随着我国高层建筑广泛兴建，桩筏基础因其适应性强、承载力高而倍受欢迎。而高层建筑桩筏基础的沉降分析和桩筏荷载分担比的确定是岩土工程领域中的热点和难点，本文在前人工作的基础上主要做了以下工作： a、本文综述了桩筏基础共同作用的发展概况和基本理论，并回顾了桩筏基础共同作用的研究状况。 b、将单桩的沉降计算结果与现场静载荷试验的结果进行对比分析，对计算模型中所涉及到的参数进行修正，以为群桩的分析提供合理的参数，达到充分利用已知信息的目的。 c、采用可考虑土分层的有限压缩层地基模型，筏板的分析采用矩形薄板单元，对E_s1-2进行深度修正得到压缩模量E_s，并通过收集到的太原地区不同深度土层模量关系进行拟和验证，采用基于弹性理论的Boussinesq应力解和Mindlin应力解分别计算桩间土中的附加应力和桩底附加应力，按照分层总和法求沉降的原理计算沉降，基于上述机理建立了桩筏基础共同作用 太原理工大学硕士研究生学位论文计算模型并用N沙汀LAB数学软件编制相应的计算程序。 d、本文通过一算例分析了几个设计参数对群桩沉降、桩顶反力分布和桩筏荷载分担比的影响，探讨了桩筏土共同作用的机理，得出桩筏基础桩顶反力随桩筏相对刚度变化的规律和沉降分布以锅底型为特征的结论。为今后设计中桩的布置和筏板厚度的选取等提供可靠的理论依据。 e、最后对太原地区三个工程实例进行分析，将实测资料与用本文分析方法计算得的结果进行对比，证明了本文方法是可行的，具有一定的实用价值。更多还原

【Abstract】 In recent years pile-raft foundation becomes more popular due to its adaptability and high bearing capacity with the development of high-rise building. Determining the settlement of pile-raft foundation and load distribution between pile and raft are the focus and the difficulty in geotechnical engineering.In this paper, based on the review of general development situation and fundamental theory of interaction of pile-raft foundation, following research works are achieved:a. Comparison has been made between calculated result of settlement for single pile and the result of static load test, parameter involved in calculation model have been modified to meet the need of calculation for group piles, so we can make good use of known information.b. Limit compression layer model has been used to consider muti-layer of soil, rectangular plate element has been applied to analysis the raft, compression modulus Es is obtained through modifying Esi.2, which has been fitted and proved by collected data about soil modulus in different depths fromTaiyuan, additional stress of ground among piles and that of pile tip are calculated by Boussinesq’ stress solution and Mindlin’ solution based on elastic theory respectively. The settlement is obtained according to the layerwise summation method. The calculating model for interaction of pile-raft foundation is built based on above mechanism and calculation program is established accordingly by using MATLAB software.c. Influence of several design parameters on the settlement of group pile, the contact pressure distribution on the top of the pile and load distribution of pile and raft, have been analyzed respectively, thus the mechanism of interaction of pile-raft foundation is discussed. In this paper, variation regular of contact pressure on the top of pile with different relative rigidity ratio of pile against raft is presented and the result that settlement distribution is characteristic of boiler bottom is obtained. All those analysis above may provide designer with reliable theoretical evidence to decide arrangement of pile and choose optimum thickness of raft.d. At the end of the paper, the applications of the method are introduced on three projects. Comparison has been made between measured data and the result of calculation. It is shown that the method of this paper is plausible and practical.更多还原